Pipe coupling

ABSTRACT

A pipe coupling, which enables pipes to be assembled with the pipe coupling by an one-touch operation while maintaining the liquid-tightness at jointing portions. In the pipe coupling, a connection tube has holding shoulders formed at opposite predetermined inner portions of the connection tube and maximum diameter portions formed at both side portions of the connection tube outside of the holding shoulders. The connection tube has an inner diameter decreasing in a direction toward both mouths of the connection tube from the maximum diameter portions. Snap rings are inserted inside of the mouths of the connection tube in a compressed state. Packing members are tightly disposed in each of the maximum diameter portions. Jaw couplings are inserted in the mouths of the connection tube and each of the jaw couplings are assembled with a plurality of fixing jaws and having engaging protuberances. The fixing jaws are arranged in a circumferential direction of each of the jaw couplings. Each of the engaging protuberances has a width smaller than an interval of a spaced portion of each of the snap rings. The engaging protuberances are engaged with inner ends of the snap ring. Elastic members are inserted between the jaw couplings and the packing members.

TECHNICAL FIELD

The present invention relates to a pipe coupling, which enables pipes tobe connected with and separated from each other by a one-touchoperation.

BACKGROUND ART

In general, the liquid-tightness and the degree of coupling have beenrecognized as the most important factors in connecting hydraulic pipeswith each other. Therefore, most of the couplings for connecting pipes,which have various shapes such as those of a linear tube, a bent tube,and a T-shaped tube, are screw-coupled with the hydraulic pipes andinclude packing members such as O-rings inserted in jointing portions,in common.

However, the usual coupling is assembled with the hydraulic pipes bymeans of a screw joint, in which case a strong jointing force isrequired and separate tightening tools are necessary in assembling thepipes with each other. Moreover, when the joint is not firmlymaintained, the liquid-tightness can be deteriorated, so that liquid canleak through joint portions, and thereby the reliability on theconnection between the pipes are deteriorated.

DISCLOSURE OF INVENTION

Accordingly, the present invention has been made to solve theabove-mentioned problems occurring in the prior art, and an object ofthe present invention is to provide a pipe coupling having an improvedconstruction, which enables pipes to be assembled with the pipe couplingby a one-touch operation while maintaining the liquid-tightness atjointing portions.

It is another object of the present invention to provide a pipecoupling, in which accessories of the coupling can be separated andeasily replaced.

It is another object of the present invention to provide a pipecoupling, by which even large pipes can be easily and exactly connectedwith each other.

In order to accomplish these objects, there is provided a pipe couplingfor connecting pipes with each other, the pipe coupling comprising: aconnection tube having changing inner and outer diameters, theconnection tube including holding shoulders formed at oppositepredetermined inner portions of the connection tube and maximum diameterportions formed at both side portions of the connection tube outside ofthe holding shoulders, each of the holding shoulders limiting a depth bywhich each of the pipes can be inserted, the maximum diameter portionsrespectively having an inner diameter much larger than an outer diameterof the pipes, the connection tube having an inner diameter whichdecreases in a direction toward both mouths of the connection tube fromthe maximum diameter portions; snap rings inserted inside of the mouthsof the connection tube in a compressed state; packing members, each ofwhich is tightly disposed in each of the maximum diameter portions; jawcouplings inserted in the mouths of the connection tube, each of the jawcouplings being assembled with a plurality of fixing jaws and havingengaging protuberances, the fixing jaws respectively having serrationsformed at a surface to be in contact with each of the pipes, the fixingjaws being arranged in a circumferential direction of each of the jawcouplings, each of the engaging protuberances having a width smallerthan an interval of a spaced portion of each of the snap rings, theengaging protuberances being engaged with inner ends of the snap ring;and elastic members inserted between the jaw couplings and the packingmembers.

In accordance with another embodiment of the present invention, there isprovided a pipe coupling for connecting pipes with each other, the pipecoupling comprising: a central connection tube having a through holeaxially formed in the central connection tube and holding shouldersformed at both ends of the through hole so as to limit a depth by whicheach of the pipes can be inserted; side connection tubes assembled atboth sides of the central connection tube in such a manner as torespectively communicate with the central connection tube, each of theside connection tube having an inner space, through which each of thepipes is inserted, and whose construction and shape have dimensionsgradually decreasing from the central connection tube toward mouths ofthe side connection tubes; packing members respectively interposedbetween the central connection tube and each of the side connectiontubes; snap rings respectively inserted inside of the mouths of the sideconnection tubes in a compressed state; jaw couplings respectivelyinserted in each of the mouths of the side connection tube, each of thejaw couplings being assembled with a plurality of fixing jaws and havingengaging protuberances, the fixing jaws respectively having serrationsformed at a surface to be in contact with each of the pipes, the fixingjaws being arranged in a circumferential direction of each of the jawcouplings, each of the engaging protuberances having a width smallerthan an interval of a spaced portion of each of the snap rings, theengaging protuberances being engaged with inner ends of the snap ring;and elastic members respectively inserted between the jaw coupling and avertical inner wall of each side connection tube, the vertical innerwall being disposed at a side of the central connection tube.

BRIEF DESCRIPTION OF DRAWINGS

The above and other objects, features and advantages of the presentinvention will be more apparent from the following detailed descriptiontaken in conjunction with the accompanying drawings, in which:

FIG. 1 is an exploded perspective view of a pipe coupling according tothe first embodiment of the present invention;

FIG. 2 is a longitudinal sectional view of the pipe coupling accordingto the first embodiment of the present invention in an assembled state;

FIG. 3 is a longitudinal sectional view of a pipe coupling according tothe second embodiment of the present invention in an assembled state,which shows the construction of the pipe coupling;

FIGS. 4 a and 4 b are transverse and longitudinal sectional views of thepipe coupling of the present invention, in a state in which the jawcoupling can be separated from the snap ring; and

FIGS. 5 a and 5 b are transverse and longitudinal sectional views of thepipe coupling of the present invention, in a state in which the jawcoupling is tightly engaged with and held by the snap ring.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, several preferred embodiments of the present invention willbe described with reference to the accompanying drawings.

FIG. 1 is an exploded perspective view of a pipe coupling according tothe first embodiment of the present invention, and FIG. 2 is alongitudinal sectional view of the pipe coupling according to the firstembodiment of the present invention in an assembled state.

Referring to FIGS. 1 and 2, the pipe coupling according to the firstembodiment of the present invention includes a hollow connection tube 10for interconnecting pipes 1 inserted into both sides of the connectiontube 10, so as to enable the pipes 1 to communicate with each other, andaccessories contained in the connection tube 10, so as to clamp thepipes 1 inserted in the connection tube 10.

The connection tube 10 has changing inner and outer diameters. That is,holding shoulders 12 are formed at opposite predetermined inner portionsof the connection tube 10, so as to limit the depth by which the pipes 1can be inserted. At both side portions of the connection tube 10 outsideof the holding shoulders 12 are formed maximum diameter portions 16,which respectively have an inner diameter much larger than the outerdiameter of the pipes 1. Further, the connection tube 10 has such ashape as that the inner diameter of the connection tube 10 decreases ina direction toward both mouths 14 of the connection tube 10, whichrespectively have an inner diameter also larger than the outer diameterof the pipes 1.

Meanwhile, the accessories include packing members 20, snap rings 30,jaw couplings 40, and elastic members 50. Each of the packing members 20is tightly disposed in the maximum diameter portion 16, so as to preventwater from leaking between the connection tube 10 and each of the pipes1.

The snap rings 30 are inserted inside of the mouths 14 of the connectiontube 10 in a compressed state. In this case, each of the snap rings 30has a form nearly like a circle as shown in FIG. 1, a portion of whichis omitted to form a spaced portion 32, which is made from elasticmaterial and thereby can be freely deformed. Consequently, the diameterof each snap ring 30 can be elastically increased and reduced under alimitation by a deformation range of the spaced portion 32, so that thesnap ring 30 can be fitted in a groove formed at an outer cylindricalsurface of a shaft or an inner cylindrical surface of a tube, therebyperforming a usual function of preventing parts from moving. In the caseof the present invention, the snap rings 30 respectively prevent each ofjaw couplings 40, which will be described later, from being separated.

The jaw couplings 40 are inserted in the mouths 14 of the connectiontube 10. Further, a plurality of fixing jaws 42, respectively havingserrations 42 a formed at a surface to be in contact with the pipe 1,are assembled with each of the jaw coupling 40 while being arranged in acircumferential direction of the jaw coupling 40. Moreover, engagingprotuberances 44, each of which has a width smaller than the interval ofthe spaced portion 32 of the snap ring 30, are formed at a portion of acircumferential surface of each jaw coupling 40 in such a manner as thatthe engaging protuberances 44 can be engaged with inner ends of the snapring 30.

The elastic members 50 are respectively inserted between the jawcoupling 40 and the packing member 20, so as to function to push the jawcoupling 40 toward the mouth 14 by means of the elastic force.

In this case, the engaging protuberances 44, each of which has a slantsurface 44 a at the side of the mouth 14 and a vertical surface 44 b atthe inner side, form a serrated shape in total, so as to prevent the jawcoupling 40 from being pushed into the connection tube 10 by an externalimpact as shown by the arrows in FIG. 2.

In the meantime, FIG. 3 is a longitudinal sectional view of a pipecoupling according to the second embodiment of the present invention inan assembled state, which shows the construction of the pipe coupling.

Referring to FIG. 3, the pipe coupling according to the secondembodiment includes a plurality of connection tubes separated from eachother and accessories contained in the connection tubes.

First, the connection tubes comprise: a central connection tube 60having a through hole 62 axially formed in the central connection tube60 and holding shoulders 64 formed at both ends of the through hole 62so as to limit the depth by which the pipes 1 can be inserted; and apair of side connection tubes 70 assembled one by one at both sides ofthe central connection tube 60 in such a manner as to respectivelycommunicate with the central connection tube 60. Each of the sideconnection tube 70 has an inner space, through which the pipe 1 isinserted, and which has a construction and a shape whose dimensionsgradually decrease from the central connection tube 60 toward the mouth72.

Further, the accessories include packing members 80, snap rings 90, jawcouplings 100, and elastic members 110. Each of the packing members 80is interposed between the central connection tube 60 and the sideconnection tube 70, so as to maintain the portions of connecting thepipes watertight.

The snap rings 90 are inserted inside of the mouth 72 of each sideconnection tube 70 in a compressed state, so as to prevent the jawcoupling 100 from being separated, which will be described hereinafter.

The jaw couplings 100 are inserted in the mouths 72 of each sideconnection tube 70. Further, a plurality of fixing jaws 102,respectively having serrations 102 a formed at a surface to be incontact with the pipe 1, are assembled with each of the jaw coupling 100while being arranged in a circumferential direction of the jaw coupling100. Moreover, engaging protuberances 104, each of which has a widthsmaller than the interval of a spaced portion 92 of the snap ring 90,are formed at a portion of a circumferential surface of each jawcoupling 100 in such a manner as that the engaging protuberances 104 canbe engaged with inner ends of the snap ring 90.

Furthermore, the elastic members 110 are respectively inserted betweenthe jaw coupling 100 and a vertical inner wall 66 of each sideconnection tube 70 disposed at the side of the central connection tube60, so as to exhibit an elastic force of pushing the jaw coupling 100toward the mouth 72 of the side connection tube 70 by means of theelastic force.

Hereinafter, described will be operations of the pipe couplingsaccording to the embodiments of the present invention.

First, a description about the pipe coupling according to the firstembodiment will be given with reference to FIGS. 1, 2, 4 a, 4 b, 5 a and5 b. When the pipes 1 are inserted into the jaw couplings 40 from themouths 14 of the connection tube 10, the pipes 1 push and carry thefixing jaws 42 into the connection tube 10 while compressing the elasticmembers 50. The pipes 1 having passed through the jaw couplings 40 cometo be in contact with the holding shoulders 12 of the connection pipe10.

In the course of the above procedure, when each of the fixing jaws 42pushed by the pipes 1 reaches the maximum diameter portion 16, thefixing jaw 42 is widened outward up to the inner diameter of the maximumdiameter portion 16 of the connection tube 10, so as to enable the pipe1 to reach the holding shoulder 12.

Thereafter, each of the fixing jaws 42 having been carried to thecentral portion of the connection tube 10 is returned toward the mouth14 of the connection tube 10 by the elastic force of the elastic member50. While the fixing jaw 42 is returned to the mouth 14, the fixing jaw42 is contracted according to a reducing inner diameter of adiameter-reducing portion 18 of the connection tube 10, so as to be intight contact with the pipe 1, thereby firmly clamping the pipe 1.

As described above, in the pipe coupling according to the presentinvention, the pipes can be assembled with the pipe coupling andconnected with each other through the pipe coupling through a simplelabor of pushing the pipes into the pipe coupling. Therefore, it goeswithout saying that the working efficiency is remarkably improved in thepipe coupling of the present invention.

In the meantime, in the pipe coupling of the first embodiment, when itis necessary to replace the packing member 20 due to its aging and thelike, the jaw coupling 40 exposed out of the connection tube 10 isrotated until the engaging protuberances 44 formed on the surface of thejaw coupling 40 are located in the spaced portion 32 of the snap ring 30as shown in FIGS. 4 a and 4 b, and then the jaw coupling 40 is separatedfrom the connection tube 10. Thereafter, the other parts aresequentially separated, so that the packing member 20 can be replaced.After the labor of the replacement, the parts are assembled according toa reverse order to the assembling order. At the final stage, as shown inFIGS. 5 a and 5 b, the jaw coupling 40 is arranged in such a manner thatthe engaging protuberances 44 of the jaw coupling 40 coincide with thespaced portion 32 of the snap ring 30, and the jaw coupling 40 isinserted into the connection tube 10. Thereafter, the jaw coupling 40 isrotated in one direction so as not to be coincide with the spacedportion 32 of the snap ring 30, so that the engaging protuberances 44 ofthe jaw coupling 40 is engaged with the inner end of the snap ring 30,thereby maintaining the assembled state.

The pipe coupling according to the first embodiment of the presentinvention as described above is proper in connecting pipes having arelatively small diameter.

A description about a pipe coupling according to the second embodimentof the present invention will be given hereinafter with reference toFIGS. 3, 4 a, 4 b, 5 a and 5 b. In the pipe coupling according to thepresent embodiment, which is proper in connecting pipes having arelatively large diameter, the pipes 1 are firstly fitted through andassembled with the side connection tubes 70, due to the difficulty ofhandling large pipes. Then, connection ends of the pipes 1 are insertedinto both ends of the central connection tube 60, and then the centralconnection tube 60 is assembled respectively with the side connectiontubes 70 by means of screws 120. The procedure of fitting the pipe 1into the side connection tube 70 is the same as that in the firstembodiment.

The reason of requiring the above procedure in the second embodiment isas follows. That is, since it is difficult to exactly fit a large pipeinto the pipe coupling, the large pipe is fitted into and fixed to theside connection tube 70, and then the pipe assembled with the sideconnection tube 70 is fitted into the central connection tube 60, so asto enable the pipes to be connected in line with each other.

Also in the present embodiment, as shown in FIGS. 4 a, 4 b, 5 a, and 5b, since the jaw coupling 100 can be separated in the same way as thatin the first embodiment, the accessories in the side connection tube 70can be replaced. However, the packing member 80 can be replaced onlyafter the central connection tube 60 is separated from the sideconnection tubes 70.

INDUSTRIAL APPLICABILITY

In the pipe coupling according to the present invention as describedabove, since the pipes can be connected with and separated from eachother through a one-touch operation, the labors of interconnecting andseparating the pipes can be easily performed. Moreover, since interiorparts including the packing members can be replaced, the life span of aproduct can be prolonged.

Furthermore, the present invention provides pipe couplings, which arerespectively proper in connecting pipes having relatively largediameters and in connecting pipes having relatively small diameters. Inresult, a proper pipe coupling can be chosen according to the dimensionof the pipes, so as to provide the labor of connecting the pipes withefficiency.

Although a preferred embodiment of the present invention has beendescribed for illustrative purposes, those skilled in the art willappreciate that various modifications, additions and substitutions arepossible, without departing from the scope and spirit of the inventionas disclosed in the accompanying claims.

1. A pipe coupling for connecting pipes with each other, the pipecoupling comprising: a connection tube having changing inner and outerdiameters, the connection tube including holding shoulders formed atopposite predetermined inner portions of the connection tube and maximumdiameter portions formed at both side portions of the connection tubeoutside of the holding shoulders, each of the holding shoulders limitinga depth by which each of the pipes can be inserted, the maximum diameterportions respectively having an inner diameter much larger than an outerdiameter of the pipes, the connection tube having an inner diameterwhich decreases in a direction toward both mouths of the connection tubefrom the maximum diameter portions; snap rings inserted inside of themouths of the connection tube in a compressed state; packing members,each of which is tightly disposed in each of the maximum diameterportions; jaw couplings inserted in the mouths of the connection tube,each of the jaw couplings being assembled with a plurality of fixingjaws and having engaging protuberances, the fixing jaws respectivelyhaving serrations formed at a surface to be in contact with each of thepipes, the fixing jaws being arranged in a circumferential direction ofeach of the jaw couplings, each of the engaging protuberances having awidth smaller than an interval of a spaced portion of each of the snaprings, the engaging protuberances being engaged with inner ends of thesnap ring; and elastic members inserted between the jaw couplings andthe packing members.
 2. A pipe coupling as claimed in claim 1, whereineach of the engaging protuberances has a slant surface and a verticalsurface, the slant surface and the vertical surface respectively beingdisposed at an inner side of the mouth, so that the engagingprotuberances form a serrated shape in total.
 3. A pipe coupling forconnecting pipes with each other, the pipe coupling comprising: acentral connection tube having a through hole axially formed in thecentral connection tube and holding shoulders formed at both ends of thethrough hole so as to limit a depth by which each of the pipes can beinserted; side connection tubes assembled at both sides of the centralconnection tube in such a manner as to respectively communicate with thecentral connection tube, each of the side connection tubes having aninner space, through which each of the pipes is inserted, and whoseconstruction and shape have dimensions gradually decreasing from thecentral connection tube toward mouths of the side connection tubes;packing members respectively interposed between the central connectiontube and each of the side connection tubes; snap rings respectivelyinserted inside of the mouths of the side connection tubes in acompressed state; jaw couplings respectively inserted in each of themouths of the side connection tubes, each of the jaw couplings beingassembled with a plurality of fixing jaws and having engagingprotuberances, the fixing jaws respectively having serrations formed ata surface to be in contact with each of the pipes, the fixing jaws beingarranged in a circumferential direction of each of the jaw couplings,each of the engaging protuberances having a width smaller than aninterval of a spaced portion of each of the snap rings, the engagingprotuberances being engaged with inner ends of the snap ring; andelastic members respectively inserted between the jaw coupling and avertical inner wall of each side connection tube, the vertical innerwall being disposed at a side of the central connection tube.
 4. A pipecoupling as claimed in claim 3, wherein each of the engagingprotuberances has a slant surface and a vertical surface, the slantsurface and the vertical surface respectively being disposed at an innerside of the mouth, so that the engaging protuberances form a serratedshape in total.